Furnace.



0. P. OSTERGREN & E. LUNDGREN.

FURNACE.

APPLICATION FILED APR, 8. 1912.

Patented Mar. 20,1917.

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FURNACE.

0. P. OSTERGREN & E. LUNDGREN.

T 0 00 I 000 o I WITNESSES:

UNITED STATES PATENT OFFICE.

.OSCAB PATRIC OSTERGREN AND EDWIN LUNDGREN, OF BROOKLYN, NEW YORK, ASSIGNOBS, BY DIRECT AND MESNE ASSIGNMENTS, TO THE WESTINGHOUSE MACHINE COMPANY, A CORPORATION OF PENNSYLVANIA.

FURNACE.

Specification of Letters Patent.

Patented Mar. 20, 1917.

Appliation filed April 8,1912. Serial No. 689,187.

To all whom it may concern:

Be it known that we, OSCAR PATRIC Os- TERGREN, a subject of the King of Sweden, and a resident of No. 431 Throop avenue, Brooklyn, New York, and EDWIN LUNDGREN, a subject of the King of Sweden, and a resident of No. 127 Clinton avenue, Brooklyn, New York, have invented certain new and useful Improvements in Furnaces, of which the following is a specification.

Our invention relates to furnaces in which the fuel is introduced on the underfeed principle, and employing an inclined elongated fuel retort or multiples thereof alternating with twyers to supply air under pressure to the fued bed and consistsof a primary feeding mechanism located externally of the retort and a secondary feeding mechanism located within the retort in combination with means to discharge'the ashes and refuse. In order to obtain a maximum of efliciency in furnacesof this type fresh fuel introduced into the fire box from a hopper is moved forward along the length of the receptacle or retort by. means of fuel rams or plungers which reciprocate in the retort and constantly supply fresh fuel thereto, the necessary air supply for the fuel being discharged through twyers adjacent to the retort.

One of the objects of our invention is to provide improved means for feeding the fuel into the retorts so that the fuel can be fed to any desired point of the fuel bed under the operators control and also to enable agitation of the fuel bed in variable directions as distinguished from the present constructions in which the feeding of the fuel and the agitation of the fuel bed is confined 'to one or two single points and always in the same plane.

A further object of our invention is to provide the air inlet pipe through which air is introduced from beneath, approximately centrally of the entire fuel bed and to provide an air chamber located substantially beneath the entire fuel bed whereby air in a desired quantity may be distributed to any point along the entire area of the fuel bed.

A .further object of our invention is to form the fuel rams or plungers in a manner whereby the fuel will be given not only the desired forward movement but will also obtain the desirable upward movement and increase agitation of the fuel bed.

mace; and Fig. 5 is a The further objects of our invention will be understood by reference to the drawings and the detailed description which follows. In the accompanying drawings Figure l is a longitudinal section through one of the.

retorts forming our under-feed furnace; Fig. 2 is a like view showing a portion of the bridge wvall and the centrally located air inlet pipe for the introduction of the air under pressure; Fig. 3 is a plan view of our improved furnace showing the mechanism for v actuating the plungers or rams and also showing the twyers, the retorts and, in dotted lines, the conduits or pipes for supplying and conveying heated air to the top of the fuel bed as will hereinafter appear; Fig. l is a longitudinal section taken through the line =Ii of Fig. 3 and showing the twyers as preferably employed in our improved furcross-sectional view taken on line 55 of F i lVe shall first describe the mechanism and operation of our improvement in feeding the fuel into the retort and over the twyers. In the accompanying drawings 1 represents a ram block which is cylindrical in form. This ram block reciprocates in a ram box 2, its reciprocal movement being imparted through the connection rod 3 which is connected to a revolving crank 4 (Figs. 2 and 3). This crank receives its revolutions by its connection to a worm gear 4 which rotates through its engagement with a worm 4 whose rotations are imparted by any suitable power connection. The ram block 1 during its forward movement in an inclined plane enters the retort 6 and through its wedge shaped face 5 progressively agitates forwardly and upwardly the fuel supplied to the retort from the hopper 7. The utility and function of this arrangement of a wedge shaped or concaved ram face is to give the mass of fuel a progressive agitation and impart to the fuel a feeding movement in an upward direction during the forward motion in the retort, resulting eventually in its distribution over the twyers adjacent to the retort. By this wedge shaped formation of the ram block 1, the resistance of the fuel is moreover greatly diminished, the fuel bed is broken up and the disadvantage of too densely packing the fuel in the retort is wholly avoided.

For the purpose of actuating our im proved auxiliary feeding mechanism hereinafter described, we connect to the primary ram block 1 a. rod 9, extending substantially the whole length of the retort 6, said rod 9 5 being secured at its other end to a Wedge shaped rear ram block 11. By means of this positive connection of the primary and rear ram blocks the reciprocations of the former will result in like reciprocations of the latter within the retort 6.

Intermediate of the ram blocks 1 and 11 a ram block 12 is secured upon the reciproeating rod 9, the front face of said ram block 12 being likewise wedge shaped and moving in unison with the ramblocks 1 and 11 by reason of its positive connection to the reciprocating rod 9. This intermediate ram block 12 is located in cooperative relation to a fuel deflecting plate 13 which, as shown in Fig. 1 is located beneath the ram block 12 and extends substantially throughout the width of the retort or fuel chamber 6.- This fuel deflecting plate 13, as shown in the particular construction of the drawings is slotted at 14 to permit passage therethrough of the reciprocating rod 9 and is pivotally mounted on a journal 15 as an axis whereon it may be swung to attain anygdesired height in the retort. The fuel guiding surface of this fuel deflecting plate 13 is preferably concaved, as shown at 13. The hand operated means whereby the fuel deflecting plate 13 may be adjusted to the desired position as to height ,in the retort, comprises a screw and nut engagement 16 and a shaft 17, hand wheel 18, whereby the turning of the hand wheel will cause the screw thread eitherto swing the fuel defleeting plate upwardly or downwardly. It will be understood, that any other or equivalent means may be employed to give the fuel deflecting plate the desired adjustment or that the ram block 12 may beconstructed to have a swinging movement relatively to the fuel deflecting plate.

The operation of our improved fuel feeding device is as follows:

The fuel is introduced ,to the retort 6 through the hopper 7 and rests upon the bottom plate 6 of the retort, the ram blocks 1, 11 and 12 being in their retracted positions. Through power imparted to the connection rod 3 the three ram blocks are then moved forward. The fuel supplied through hopper 7 to the upper end of the retort 6 is now moved forward and upward by the forward movement of the ram block 1.

During the rearward movement of the ram block 1 a further supply of fuel is admitted through hopper 7. During the subsequent forward movements of the ram block 1 the fuel advanced by the ram block 1 during the prior forward movement is picked up by' the forward movement of the intermediate ram block 12 and is carried thereby for- .of the furnace.

wardly and upwardly along the concaved surface 13 of the fuel deflecting plate 13.

During the further reciprocation of the ram. blocks 1, 11 and 12 the fuel carried by the ram block 12 will drop into the portion 11 of the retort 6 below the fuel deflecting plate 13. When this space 11 of the retort is substantially filled theram block 11, being provided with a wedge shaped face 11" will in its retracting movement burrow ram blocks after the retortis filled and the twyers covered with fuel results in the continuous feeding of the fuel and the agita tion required for the maximum of efficiency.

If desired, in starting the furnace the fuel deflecting plate 13 may be in'its depressed osition so that the regulation bf the-fuel will be accomplished without its cooperagilonkand entirely by the stroke of the ram oc s.

The main difficulty which has been found in -furnace stokers of the kind here generally referred to has resided in the fact that with the horizontal ramming stroke of the hopper would be built up 'to an excessive height and density in the retorts and over the twyers while the twyers more rethe rams the portion of the fuel bed nearest mote from the hopper would be but sparsely covered with fuel resulting in the retardatlon of combustion at the front part of the furnace in view of the fact that the air would but slowly penetrate the mass of-fuel densely accumulated toward the front part This difficulty is entirely overcome by our present invention wherein the height of the fuel deflecting plate regulates the depth of the fuel at any portion of the fuel bed. While we have herein shown this fuel deflecting plate as adjustable it will be understood that in given cases the same may be'fixed and effectively control the distribution of fuel. A further difficulty in prior structures has resulted from the density of fuel produced by the impacting of ram blocks having a vertical face, tending to compress and pack the fuel. The wedging action of the ram blocks here described overcomes this objection and secures the desirable result *ofconstant agitation of the for the introdilction into the furnace of air under pressure. In the prior constructions the forced draft supply is introduced through a wind-box transversely underlying the fuel bed near the lowermost portion of the retort and twyers where the fuel bed is comparatively thin and consists largely of burnt-out fuel. ashes and clinkers.

The result of this arrangement is that the forced draft in a straight course passes through the sphere of least resistance, this being the portion of the fuel bed where the fuel is thinnest and almost burnt out. The portion of the fuel bed, on the contrary, nearest the supply hopper wherein the "volatile matter requires a much greater supply of air and the fuel bed is ofgreater depth, is in the prior structures inadequately provided for. In our construction we provide a centrally located forced draft pipe 20 beneath and communicating with a chamber 21 underlying the entire series of openings "22 of thetwyers 8. The.introduction of the air under pressure into the chamber 21 above the draft pipe 20 results in a generaland equal distribution of the air throughout the entire series of twyers 8 while the employment of a swinging damper '23 in' said pipe 20 permits of the exact regulation of air admission to said chamber 21 as the conditions may require. The bottom plate 23 of the chamber 21 is provided with the opening 23" through which this supply pipe delivers its forced draft.

For the purpose of regulating the quantity and pressure of air to be supplied to either the upper or lower portions of the fuel bed, we provide in the underlying chamber 21 a partition wall 21 extending throughout the width of said chamber il and provided with a series of openings 26 and dampers "27 which may be arranged to slide over the said openings 26 by means ,of hand operated shaft 27 having a gearing 28 which meshes with a rack 29 secured to the sliding dampers 27, whereby a rotation of the hand wheel will cause the gear 28 to mesh with the teeth of the rack 29 and slide the dampers 27 any desired distance over the openings 26 in said partition wall. 'hen it is desirable in view of the condition vof the fuel lying on the lower portions of the fuel bed to increase or decrease the air supply and divert a greater or less volume to the lower portions of the fuel bed, the dampers 27 are manipulated to permit air admission as the condition of the lower fuel bed may require.

A further feature. of our improved furnace construction consists in the introduction of heated air. by means ofpipes 2t which extend lengthwise beneath the twyers 8. At the upper end of the pipe the same is provided with a bent portion 2} communicating with an upper distributing chamber 25 provided with perforations 25 through which the air will pass over the fuel accumulated in the upper portions of the fuel bed. The air supplied for these pipes 2% is obtained likewise through'the draft pipe 20 and the chamber 21 and by reason of its passage through the. chamber 30, formed by a top plate 30, rear plate 30 and bent portion 30, will reach the outlet perforabeneath alternate series of twyers 8 but if desired it will, of course, be understood that .these pipes may be located in each of the series of twyers. The advantage of this construction is that the top plate 30 is protected by the circulation of air beneath it; that the clinkers and ashes passing over this plate may be discharged on to the dumping plate at a low temperature and that the circulating air is heated in the chamber 30 prior to its passage into the pipes 24 and over the upper fuel bed.

Another feature of our invention is the employment of steam pipes 31 adjacent to the side walls of the furnace, these pipes being provided with perforations whereby steam emitted therethrough will prevent the formation of clinkers upon the surfaceof' I wall of the furnace and are provided with the usual valves 31 to regulate the amount of steam admitted. e

We claim:

1.' In an underfeed, forced draft'furnace, the combination of a fuel support comprising an inclined, elongated fuel retort, twyers ad acent thereto, an'air chamber underlying said fuel support and twyers, a partie tion wall dividing said chamber into a plurality of compartments, means provided in said partition wall for regulating the admission of air from one into the other of said compartments, a conduit in conimunication with one of said compartments, said conduit extending longitudinally beneath the fuel support, and terminating at a point above the fuel bed( to deliver the heated air from said compartment above the fuel bed.

.2. In an underfeed forced draft furnace the combination of a fuel support comprising an inclined elongated fuel retort, twyers adjacent thereto, an air chamber underlying said fuel support and twyers, a secondary chamber at the lower end of the retort, a

conduit in communication with said secondary chamber, extending longitudinally beneath said fuel support from said secondary chamber and terminating at a point above the fuel bed to deliver heated air at and having their fuel supporting surfaces elevated above the bottoms of the retorts, a fuel hopper communicating with at least one of said retorts, means for introducing fuel from said hopper into said retort below the surface of the fuel maintained on the fuel supporting surfaces, an air chamber underlying the retorts and said fuel supporting twyer blocks, a partition dividing said chamber into a plurality of compartments,

' means provided within the partition for,

regulating the delivery of air from onecompartment into another, and means for delivering air under pressure to one of said compartments.

'5. In an underfeed forced draft furnace, the combination of downwardly inclined elongated fuel retorts. downwardly inclined fuel supporting surfaces alternately arranged with the retorts and comprising fuel supporting twyer blocks located in overlapping relation and having their fuel supporting surfaces elevated a ove the bottoms of the fuel retorts, means for delivering fuel into the upper ends of the retorts below the surface of the fuel maintained on said fuel supporting surfaces, an air chamber underlying said fuel supporting twyer blocks and said retorts, a partition extending at an angle to the retorts and dividing the chamber into forward compartment communi: eating with the upper ends of the fuel supporting surfaces, and a rear compartment communicating with the lower ends of the fuel supporting surfaces, means for delivering air under pressure to the forward compartmen ineans provided within the partis tion for establishing communicat n between the compartments and adjustable means for regulating the flow of air from the forward to the rear compartment.

6. an underfeed stoker, a downwardly inclined fuel retort extending from the front to the rear of the stoker, downwardly inclined fuel supporting twyers located on each side of said retort and extending from the front to the rear of the stoker, a hopper communicating with the upper end of the retort, reciprocable means located in the hopper for forcing fuel therefrom into the gitudinally extending .fuel support having a trough-shaped retortformed therein, a ram.

block for moving fuel into and through the retort, and an adjustable fuel deflector located in the retort within the path of travel of the fuel through the retort and forming a part of the fuel support. I

8. In a furnace, the combination of a downwardly inclined fuel support com ris ing a trough-shaped retort extending rom the front to the rear of the furnace and longitudinally extending fuel supporting twyers located on each side of the retort with their fuel supporting surfaces elevated above the floor of the retort, reciprocable ram blocks for introducing fuel into said retort and for moving fuel across the fuel support,

.and anadjustable deflector located, m the bottom ofthe retort and cooperating with the ram blocks to vary the depthofthe fuel bed at different points along the fuel support. K

9. In an underfeed furnace, the combination of a downwardly inclined fuel support comprising longitudinally extending troughshaped fuel retorts, and alternately arranged fuel supporting twyers having their fuel supporting surfaces elevated above the bottoms of the retorts, a fuel hop r communicating with the forward ends 0 the retorts, means for introducing fuel from said hopper into said retorts below the surface of the fuel bed maintained on said fuel support, a reciprocable fuel ram block having a wedge shaped fuel feeding face located in each retort, and an adjustable fuel deflector located in the bottom of each retort between the fuel feeding means and the ram block.

10. In an underfeed forced draft furnafi the combination of downwardly inclin elongated fuel retorts, downwardly inclined p fuel supporting surfaces alternately ar-r ranged withthe retorts and each comprising removable fuel supportingand air delivery means located in inclined relations and extending from the front of the furnace down wardly to substantially the lower ends ofthe retorts and having their fuel supporting surfaces elevated above the bottom of the retorts, means for delivering fuel into the upper ends of the retorts and below the surface of the fuel maintained on the fuel supporting surfaces, an air chamber underlying said fuel supporting surfaces and said retorts, means extending atan angle to the retorts and dividing the chamber into a forward compartment communicating with the upper portions of the fuel supporting surfaces, and a rear compartment communicating with the lower portions of the fuel supporting surfaces, means for delivering air under pressure to the forward compartment, 15 and means for delivering air ata less volume and pressure to the rear compartment.

In witness whereof we have hereunto set' our hands in the presence of two subscribing witnesses.

OSCAR PATRIC OSTERGREN.

EDWIN LUNDGREN. Witnesses:

EUGENE EBLE,

JOHN AKEHLENTEGK. 

